When components fail in the field or during testing, surface-level inspections often leave more questions than answers. That’s because many defects—especially in PCBs, capacitors, and integrated circuits (ICs)—are internal and invisible without the right tools.
At Cross Section Lab, we specialize in using mechanical cross sectioning to reveal the hidden failure mechanisms that other methods miss.
Here’s how cross sectioning works—and why it’s essential for electronic component failure analysis.
What Is Mechanical Cross Sectioning?
Mechanical cross sectioning involves cutting into a component, grinding and polishing it to expose an internal plane, and inspecting that polished surface under high magnification.
It’s destructive, but it allows for direct visualization of internal structures—something you simply can’t get from external visual inspection, X-ray, or even CSAM.
Why Hidden Defects Matter
Internal component defects often go undetected until devices fail during:
- Field use
- Environmental stress testing (e.g., thermal cycling, vibration)
- In-circuit testing or burn-in
These hidden defects include:
- Delamination in PCBs or IC packages
- Voids in solder joints or die attach
- Cracked dielectric layers in capacitors
- Improper copper plating in vias
- Contamination between material layers
Identifying these issues early can save tens of thousands in recalls, RMAs, or lost customer trust.
How Cross Sectioning Uncovers Defects in Key Components
1. Printed Circuit Boards (PCBs)
Cross sectioning PCBs can reveal:
- Delamination between layers or solder mask separation
- Thin or missing copper plating in vias
- Voids in through-holes or microvias
- Cracks from mechanical or thermal stress
- CAF (Conductive Anodic Filament) growth
These issues often originate in manufacturing defects or design flaws and lead to intermittent failures or catastrophic shorts.
🛠 Example: A field failure traced to a microvia void is confirmed via cross section, prompting a PCB supplier change.
2. Capacitors
Common hidden defects in capacitors include:
- Cracks in ceramic dielectric materials
- Voids in electrolytic layers
- Swelling or internal delamination
- Degraded electrode interfaces
These issues can cause:
- Drifting capacitance
- Sudden shorting
- Heat-related failure during load cycles
🧪 Cross sectioning helps identify whether the failure came from mechanical stress, manufacturing process, or in-circuit overvoltage.
3. Integrated Circuits (ICs)
Cross sectioning ICs helps identify:
- Die attach voids or poor thermal contact
- Wire bond lift or heel cracks
- Delamination between mold compound and die
- Die cracking from thermal or mechanical stress
- Foreign material contamination
These defects are often not detectable via CSAM or X-ray alone.
A cross sectioned IC revealed a cracked passivation layer from packaging stress—something invisible to X-ray and CSAM but confirmed optically.
The Cross Sectioning Advantage
| Method | Detects Surface Defects | Detects Internal Defects | Confirms Root Cause | Provides Measurements |
|---|---|---|---|---|
| Visual/Optical | ✅ | ❌ | ❌ | ❌ |
| X-ray | ✅ (some) | ✅ (density only) | ❌ | ❌ |
| CSAM | ❌ | ✅ (voids, delam) | ❌ | ❌ |
| Cross Sectioning | ✅ | ✅ | ✅ | ✅ |
Cross sectioning gives you visual proof, dimensional data, and material-level insights into the failure.
When Should You Use Cross Sectioning?
Use mechanical cross sectioning if:
- You suspect internal defects after CSAM or X-ray
- A component has failed without obvious external damage
- You need to verify supplier quality or production consistency
- You need to provide conclusive failure evidence to a customer or regulatory body
Why Choose Cross Section Lab?
At Cross Section Lab, we help engineers, quality managers, and product teams get to the bottom of failures quickly—with:
- Clean, high-resolution cross sections
- Expert analysis from experienced failure analysts
- Fast turnaround times and clear reports
- Support for PCBs, ICs, capacitors, and more
Whether you’re troubleshooting a field return or qualifying a new supplier, we’ll help you find the root cause—not just the symptom.